docs: def apply_region_configs(env_config):
      """Override default env configs with region specific configs and nest
      all values under a region
  
      Args:
          env_config (dict): The environment specific config.
  
      Return:
          dict: Newly updated dictionary with region overrides applied.
      """
      new_config = env_config.copy()
      for region in env_config.get('regions', REGIONS):
          if isinstance(env_config.get('regions'), dict):
              region_specific_config = env_config['regions'][region]
              new_config[region] = dict(DeepChainMap(region_specific_config, env_config))
          else:
              new_config[region] = env_config.copy()
      LOG.debug('Region Specific Config:\n%s', new_config)
      return new_config